From: Willy Tarreau <w@1wt.eu>
Date: Tue, 4 May 2021 14:27:45 +0000 (+0200)
Subject: BUG/MEDIUM: cli: prevent memory leak on write errors
X-Git-Tag: v2.4-dev19~154
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=18b2a9dd874b66acca304580047fa6b3c16da1e3;p=thirdparty%2Fhaproxy.git

BUG/MEDIUM: cli: prevent memory leak on write errors

Since the introduction of payload support on the CLI in 1.9-dev1 by
commit abbf60710 ("MEDIUM: cli: Add payload support"), a chunk is
temporarily allocated for the CLI to support defragmenting a payload
passed with a command. However it's only released when passing via
the CLI_ST_END state (i.e. on clean shutdown), but not on errors.
Something as trivial as:

  $ while :; do ncat --send-only -U /path/to/cli <<< "show stat"; done

with a few hundreds of servers is enough see the number of allocated
trash chunks go through the roof in "show pools".

This needs to be backported as far as 2.0.
---

diff --git a/src/cli.c b/src/cli.c
index 162daa62d2..b60a030c03 100644
--- a/src/cli.c
+++ b/src/cli.c
@@ -832,6 +832,7 @@ static void cli_io_handler(struct appctx *appctx)
 			 */
 			si_shutw(si);
 			free_trash_chunk(appctx->chunk);
+			appctx->chunk = NULL;
 			break;
 		}
 		else if (appctx->st0 == CLI_ST_GETREQ) {
@@ -1078,6 +1079,9 @@ static void cli_io_handler(struct appctx *appctx)
  */
 static void cli_release_handler(struct appctx *appctx)
 {
+	free_trash_chunk(appctx->chunk);
+	appctx->chunk = NULL;
+
 	if (appctx->io_release) {
 		appctx->io_release(appctx);
 		appctx->io_release = NULL;